It's good to know that you're genuinely concerned for her. Here are some things that I think you should definitely try for her: First get her into speech therapy soon, because at a young age you're likely to overcome stuttering and your mind can easily adopt smooth speech patterns. Therapy would definitely help. Secondly make her feel confident in herself. I have seen that self doubts like ( I'm not good , or I'm not doing great etc.. ) can affect speech patterns and overall confidence. If she's confident enough and has great support, she'll soon overcome it. Lastly, do have little conversation sessions or storytime sessions with her at home. Ask her about random things or things she loves to talk about. It would help her. Or you can ask her teachers separately if someone bully her because of this..